m-Trifluoromethyl benzyl nitrile is described by Fellig et al. in U.S. Pat. No. 3,573,032 as a useful intermediate for herbicidal compositions. m-Trifluoromethyl benzyl nitrile is represented by formula (I). ##STR1## Fellig et al. disclosed the preparation of (I) by reacting sodium cyanide and the appropriate benzyl chloride in aqueous acetone, dimethylformamide (DMF) or dimethylsulfoxide (DMSO) as a reaction medium. In aqueous acetone, the reaction proceeds very slowly. In DMF, a 40 to 50 percent yield is obtained in about 5 hours at from 60.degree. C. to 70.degree. C. In DMSO, a 60 to 80 percent yield is obtained in 1 to 2 hours at 80.degree. C. with no unreacted benzyl halide remaining. Because of the high yields and short reaction times, DMSO has heretofore been the preferred reaction medium.
Prior to this invention, anhydrous solvents were required to create a homogeneous phase that would allow the reaction between the chloride and cyanide reactants to occur. The anhydrous solvents are costly.
This invention provides an integrated, efficient process for the production of m-trifluoromethyl benzyl nitrile in high yields and purity and under mild reaction conditions as desired by those skilled in the art.